I went to one Celtic-Rangers match back in the seventies and spent the whole time cowering while angry and vituperative men roared out murderous insults and jumped up and down all around me. I was a tiny little thing and looked about ten.
The most interesting thing I saw was the innovative way people made use of empty beer cans. They used two as stilts to get a better view, and any others were copiously weed into and hurled at the opposition. There were rivers of wee coursing down the terrace by the end of the match, and fights breaking out all over. I adore people-watching, and I was partly terrified and partly fascinated.